The name Guanabara comes from the Tupi-Guarani language, goanã-pará, from gwa "bay", plus nã "similar to" and ba'ra "sea". Traditionally, it is also translated as "the bosom of sea."
There are more than 130 islands dotting the bay, including:
The bay is crossed by the mighty Rio-Niterói Bridge (long and with a central span high) and there is heavy boat and ship traffic, including regular ferryboat lines. The Port of Rio de Janeiro, as well as the city's two airports, Galeão - Antônio Carlos Jobim International Airport (on Governador Island) and Santos Dumont Airport (on a landfill next to downtown Rio), are located on its shores. The Federal University of Rio de Janeiro main campus is located on the artificial Fundão Island. A maze of smaller bridges seamlessly interconnect the two largest islands, Fundão and Governador, to the mainland.
Guanabara's Bay, surrounded by luxuriant tropical forests, beaches, strangely-shaped rocks and peaks, and a backdrop of the high mountains of Serra do Mar, is bordered by one of the most beautiful cities in the world, so it is considered one of the world's premier tourist spots.
Unfortunately, due to urbanization, deforestation and pollution of its waters with sewage, garbage, oil spills, etc., Guanabara Bay's ecosystem, which used to be incredibly rich and diversified in the past, has suffered a lot, particularly along its mangrove areas. Recovery measures are currently being tried, but not on the scale needed, so the pollution remains.
Guanabara Bay was discovered in January 1, 1502 by Portuguese explorer Gaspar de Lemos, who named it Rio de Janeiro (January River), because they thought it was a large river coming to the sea. Natives of the Tamoio and Tupiniquim tribes inhabited the shores of the bay. After its initial discovery, no significant European settlements were established until French colonist and soldiers, under the Huguenot Admiral Nicolas Durand de Villegaignon invaded the region in 1555 to establish the France Antarctique. After a brief stay on Lajes Island, they moved to Serigipe Island, near the shore, and built there Fort Coligny. After they were expelled by Portuguese military expeditions in 1563, the colonial government built fortifications in several points of Guanabara Bay, rendering it almost impregnable against a naval attack from the sea. They were the Santa Cruz, São João, Lajes and Villegaignon forts, forming a fearsome crossfire rectangle of big naval guns. Other islands were adapted by the Navy to host naval storehouses, hospitals, drydocks, oil reservoirs and the National Naval Academy.